Pseudothrombocytopenia
In pseudothrombocytopenia is a phenomenon in which false low in the laboratory determination of numbers of platelets can be issued. Per se, pseudothrombocytopenia is not necessarily based on a disease value, but other diseases can cause this fact:
EDTA-induced pseudothrombocytopenia
If the platelet count is determined using an EDTA sample from the patient's blood and the presence of autoantibodies leads to aggregation of the platelets in the EDTA blood, these will not be recognized in the laboratory determination, since only non-aggregated platelets are included in the count and thus an incorrectly low measured value to produce. These aggregates cannot be seen in the small blood count and require a complete blood count, as an alarm indicates the presence of these aggregates. In order to rectify the error, a new blood sample must be evaluated with a special tube ( citrated blood or using thrombo-exact ). Patients who are affected by EDTA-induced pseudothrombocytopenia should only receive blood counts with the above-mentioned sample tubes and, if necessary, carry an identification document (such as an anticoagulation card or similar) with them that informs the doctors treating further about this circumstance and any not indicated therapy attempts prevented.
Satellite phenomenon
This describes an accumulation of platelets on leukocytes, which also leads to an incorrectly low count. This cannot be further differentiated in the small blood count, but the large blood count shows an abnormal leukocyte size, which should then be checked by means of a microscopic follow-up check.
Macro-platelets
In diseases such as MDS or in macrothrombocytopenia such as Bernard-Soulier syndrome , the incorrect measurement value is caused by an abnormal size of the platelets. The platelets cannot be correctly recognized in the small blood count and it is necessary to carry out an additional optical measurement in the reticulocyte canal in the large blood count.
